Outdoor units for housing standard electronic components inside are well known from the art. An outdoor housing must be weatherproof so that no water intrusion can occur. This can be indicated by that the housing fulfills an Ingress Protection Rating of for instance IP X5 according to the International Electrotechnical Commission standard IEC 60529. Weatherproofing is normally done by using a rubber gasket or similar to seal the parts of the housing. However if a unit is completely air tight with no ventilation, heavy rain can give rise to negative pressure inside the unit. This is due to the fact that the heated air inside the unit will cool down rapidly during rain causing the pressure inside to drop. The suction force of the negative pressure can be of such magnitude that water can pass the gaskets leading to that the electronic components are subjected to water. This may give rise to malfunctions of the electronic components.
The solution to this problem is to make a ventilation opening for pressure equalization in order to equalize any negative pressure that arises. The pressure equalization must however be done rather quickly in order to avoid build up of negative pressure inside the unit. One existing solution is to use a water tight membrane such as Gore-Tex® to hinder water from entering the ventilation opening. The pressure equalization in these products are slow leading to that negative pressure may be present long enough for water intrusion to occur.
There is thus a need for an improved housing for electronic components where the above mentioned problems are at least partly avoided.